LARAMIE, Wyo. — An investigation is under way after someone replaced an American flag with a Nazi flag at a park in southeastern Wyoming.

The Laramie Boomerang reports police found the crumpled American flag shoved in the corner of the band shell at Washington Park on Monday morning. Officers folded it and then hoisted it back up the city-owned flagpole, and the Nazi flag was taken as evidence.

Jeremy Shaver with the Anti-Defamation League says it’s “appalling and outrageous” that someone would replace the American flag with “an ugly symbol of the Nazi regime.” He also thanked Laramie police for investigating the incident as a potential bias crime.

Lt. Gwen Smith says the discovery is among a very few cases in the city in recent memory that has an obvious bias component.